ZnO nanowires grown on SOI CMOS substrate for ethanol sensing

Santra S., Guha P. K., Ali S. Z., Hiralal P., ÜNALAN H. E., Covington J. A., ...More

SENSORS AND ACTUATORS B-CHEMICAL, vol.146, no.2, pp.559-565, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 146 Issue: 2
  • Publication Date: 2010
  • Doi Number: 10.1016/j.snb.2010.01.009
  • Journal Name: SENSORS AND ACTUATORS B-CHEMICAL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.559-565
  • Keywords: SOI CMOS, Gas sensor, Zinc oxide nanowires, Ethanol sensor, GAS SENSORS, DOPED ZNO, NANOROD, FILMS, HYDROGEN, NO2
  • Middle East Technical University Affiliated: Yes

Abstract

This paper reports on the integration of zinc oxide nanowires (ZnO NWs) with a silicon on insulator (SOI) CMOS (complementary metal oxide semiconductor) micro-hotplate for use as an alcohol sensor. The micro-hotplates consist of a silicon resistive micro-heater embedded within a membrane (composed of silicon oxide and silicon nitride, supported on a silicon substrate) and gold bump bonded aluminum electrodes that are used to make an ohmic contact with the sensing material. ZnO NWs were grown by a simple, low-cost hydrothermal method and characterised using SEM, XRD and photoluminiscence methods. The chemical sensitivity of the on-chip NWs to ethanol vapour (at different humidity levels) was characterised at two different temperatures namely, 300 degrees C and 400 degrees C (power consumption was 24 mW and 33 mW, respectively), and the sensitivity was found to be 0.1%/ppm (response 4.7 at 4363 ppm). These results show that ZnO NWs are a promising material for use as a CMOS ethanol gas sensor that offers low cost, low power consumption and integrated circuitry. (C) 2010 Elsevier B.V. All rights reserved.